The UK Supreme Court yesterday ruled that 27 ‘black spider’ memos sent to the government by Prince Charles in 2004-5 may be published. Judges overruled a bid by Dominic Grieve, the former attorney general, to gag publication. Thoughts that Charles has previously shared only with his mother’s ministers and sympathetic root vegetables may now see the light of day. In response to the Supreme Court decision, the prime minister shared his ‘disappointment’ with a grieving nation, while the prince’s office said that ‘Clarence House is disappointed that the principle of privacy has not been upheld.’

No doubt a public figure is entitled to privacy, even one whose inner life has metonymied into the clay of ‘Clarence House’; it seems mansions have feelings, too. But the concept of royal privacy has a sticky history. It can be argued that the origins of modern governance lie in Henry VIII’s lavatory arrangements, where the Groom of the King’s Close Stool – a flunkey on hand to deploy a sponge, ramrod-fashion, at the critical moment – occupied a key role in Privy Chamber administration. Here ‘privy’, as in the still-extant Privy Council, does duty for ‘secret’ as well as ‘private’, and there lies the rub. For most people, private and public stand distinct. From a royal’s eye view, though, as affairs of state are personal, privacy is a more a matter of official secrecy. This is how the dauphin can have have his Duchy Original organic English white muffin and eat it. His jottings jump the queue of green-ink nutter letters to ministers, but when charged with wielding influence, the privacy card remains on hand.

David Neuberger, for the Supreme Court, observed that publication couldn’t be stifled ‘simply because, on the same facts’ the attorney general happened to take ‘a different view from that adopted by a court of record’ – the tribunal set up under the Freedom of Information Act 2000 – ‘after a full public oral hearing’, even if Grieve’s view was reasonable. Neuberger’s judgment, endorsed 5-2 by the court, in effect says that a private opinion, even that of a government official, has no more than private standing when set against that of a legally competent authority such as the FoI tribunal.

Neuberger’s views on public accountability aren’t universally shared. It isn’t only the prince who clings to a Tudor vision of government. Another Henrician innovation was to bring in the ‘omnicompetence’ of parliamentary statute as a tool of the royal will. According to Wednesday’s Sun, Cameron had promised Charles legislation to ban the letters’ release. After the verdict, the prime minister voiced the ‘principle’ that senior royals should be ‘able to express their views to government confidentially. I think most people would agree this is fair enough’ – fair enough, that is, if you think a private family should be able to lean on politicians to modify democratic decisions. It’s a strange claim for a politician to make in the run-up to an election.

After the verdict, the former MP, convicted fraudster and demoted Privy Councillor Denis MacShane, who had access in government to some of Charles’s letters, suggested on Twitter that publication may prove disappointing. No doubt the memos advance Charles’s vision of tweed and free-range yokels. Yesterday’s decision, apart from cutting back secrecy, may serve a useful proleptic purpose, in making him less likely to bend ministers’ ears, though he can take comfort from King Carl XVI Gustaf, who recently summoned Sweden’s foreign minister, Margot Wallström, to the palace after she criticised the repression of women in Saudi Arabia, to howls of protest from Swedish arms exporters. But maybe Charles’s mother is doing her bit for the firm’s long-term interests. Sovereigns in Spain, Belgium, the Netherlands and the Vatican, all of them considerably younger than the queen, have recently bowed out; you can understand Elizabeth’s reluctance to lob Charles the orb.

Please forgive me if this seems pedantic, but any private family ‘can lean on politicians to modify democratic decisions’, by writing to its MP or to government ministers. Not many private families would expect their letters or e-mails to be published. So what’s different about the royal family? Is it that they are more likely to be taken seriously than anybody else? Probably not: politicians are generally pretty focused on winning votes, and the royal family don’t have votes.

The real issue is that the monarch has one extremely important job, and only one, which is to oversee changes of government after general elections, and sometimes to appoint Prime Ministers at other times. Only a monarch who failed to understand the importance of that job, or considered it intolerably boring, would compromise her or his ability to perform it properly by taking sides on political issues. What the monarch’s, or future monarch’s, views are is completely irrelevant: the crucial thing is that she or he should keep them to her or himself. Whether the letters are published or not doesn’t seem to me to matter much. What does matter is that they were written in the first place.

I used to work in the ‘correspondence unit’ of a government department. Letters from members of the public would be answered by civil servants – those who worked on the policy area concerned would copy & paste whatever the department’s line was on the issue, I’d format it as a letter, print it out and sign it myself on behalf of the department. Only letters from MPs, and very senior individuals in business or the third sector, actually got onto the Minister’s desk.

Obviously any private individual is entitled to write to a government Minister, the point is they don’t all get the same hearing.